Die for forming dental backings.



' D. H. CARPENTER.

DIE FOR FORMING DENTAL BAGKINGS. APPLIOATION FILED APR.29, 1913.

I 1,0'?,8Q9, Patented N0v.18,1913.

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DELOS H. CARPENTER, OF MINNEAPOLIS, MINNESOTA.

DIE FUR FORMING DENTAL BACKIN GS.

Specification of Letters Patent.

Patented Nov. 18, 1913.

Application filed April 29, 1913. Serial No. 764,325.

Minnesota, have invented certain new and useful Improvements in Dies for Forming Dental Backings, of which the following is a specification.

In mounting artificial tooth facings and in so-called removable bridge-work. it is customary to provide a metal backing having a tongue and groove connection with the facing or a slip-joint between the bridge and the abutments. It has been difficult to shape the tongue of the backing so that it will fit the groove and slide easily therein and after the tongue has been fitted it is frequently bent or distorted in trimming the backing, requiring another tedious process of fitting before the backing can be cemented to the facing. This applies to the telescoping sections of the bridge slip joint, as well as to the backing for the artificial facing.

The object of my invention, therefore, is to provide a tool by means of which a tongue can be easily and quickly formed in the backing and one which will be uniform from end to end, Will slip easily into the groove and if distorted in trimming, the backing can be quickly restored to "its original form.

A further object is to provide a device by means of which a backing can be produced which will be less expensive than the twopiece backing now on'the market.

A further object is to provide a device by means of which considerable time and labor pan be saved in the forming of a metal backmg. 4

Other objects of the invention will appear from the following detailed description.

The invention consists generally in various constructions and combinations, all as hereinafter described and particularly pointed out in the claims.

In the accompanying drawings forming part of'this specification,Figure l is a perspect-ive view of a metal backing plate folded along the middle line, preparatory to insertion into the die, Fig. 2 is a similar view, illustrating a convenient means for gripping the backing plate and pressing the edges thereof together, Fig. 3 is a view of the die, showing the looped portion of the backing plate inserted into the groove therein, Fig. 4 illustrates the form assumed-by the backing plate when the die is placed on a block of lead or similar substance andstruck with a hammer or mallet, Fig. 5 is an end view of ,the die, Fig, (3 is a detail sectional view through an artificial facing, showing the position of the backlog plate tongue therein,

Fig. 7 is a rear view of Fig. 6, Fig. 8 is a perspective view of the plate, fashioned to fit the facing, Fig. 9 is a sectional view on the line rcm of Fig. 7, Fig. 10 illustrates the manner of fashioning two plates in forniing a slip-joint for the bridge-work, Fig. 11 is a perspective view of two telescoping backing plates assembled to form a'slipjoint.

In the drawing, 2 represents a die adapted for mounting on the end of a shank 3, as by means of a stud 4 and a socket 5 in the shank. The die has a face 6 in which a narrow slot 7 is formed, extending from side to side of the die. This slot has substantially parallel side walls and communicates with a groove 8 which is circular in cross section and also extends from side to side of the die and with the slot 7 has open ends to allow the insertion of the backing plate or its removal at either end of the groove. This 'cd to form a backing for an artificial tooth facing 10. This facing has various forms and sizes and has a groove 11 in its rear face and may be purchased in the market ready for use.

To fit the backing plate to the groove of the facing I first bend the plate 9 along the middle portion thereof, shown in Figs. 1 and 2. I then insert the looped portion thereof into the slot 7 of the die and spread the edges of the plate, as indicated in Fig. 3, and place the die on some suitable substance, such as a block of lead 12, and then strike the shank of the die a quick blow with a mallet or hammer, whereupon the plate will be flattened against the face of the die and the looped portion in the groove of the die will conform to and fit snugly against the walls of the groove and will be uniform in shape and size from end is end. Upon raising the die from the lee 1, the loop may he slipped out of either end of the die and fitted into the groove of the facing.

Backings for the purpose described ere usually made in two pieces, eonsistinq" thin piece of metal with a tongue of soldered thereon. This is an expensive construction and often after the backing has been fitted the tongue will become twisted or distorted,

necessitating the expenditure of "considerable time and labor in again fitting it to the facing. 'By forming the backing plate with. the die, as shown and described here in, the tongue may be made absolutely uniform from end to end and should it become bent or distorted in any way it may be easily and quickly re-struek. A great deal of time and labor is thus saved over the ordinary process of fitting these backing plates to an artificial tooth When the facing and the backing plate have been fitted, they may be cemented together in the usual Way. The same tool may be used for forming plates used in slip-joint bridge Work, as indicated in Figs. 10 and 11, wheretwo plates are shown, one upon another, with their looped portions fitting one Within the other in the groove of the die, so that when the tongues are formed or struck out together they will telescope with one another, as shown in F ig. 11, and thus insure the perfect fitting of one section of to the points when the pie I claim as my inve l. A one-piece die nee head having a fiat die slot extending trensve face and an alining e circular in a with said siot, said slot ant open ends ii one-prone 1 head having a. (he

stantiell circular across the face or and open at a. slot in its race it pal e Wen-s and common and also open 

